|
Climacosphenia Elegans
''Climacosphenia elegans'' is a species of marine pennate diatoms in the order Fragilariophyceae Fragilariophyceae is a group of pennate diatom The order Pennales is a traditional subdivision of the heterokont algae known as diatoms. The order is named for the shape of the cell walls (or valves or frustules) of pennate diatoms, which a .... References External links * ''Climacosphenia elegans'' at the World Register of marine Species (WoRMS)''Climacosphenia elegans'' at algaebase Species described in 1901 Fragilariophyceae {{Diatom-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eukaryote
Eukaryotes () are organisms whose cells have a nucleus. All animals, plants, fungi, and many unicellular organisms, are Eukaryotes. They belong to the group of organisms Eukaryota or Eukarya, which is one of the three domains of life. Bacteria and Archaea (both prokaryotes) make up the other two domains. The eukaryotes are usually now regarded as having emerged in the Archaea or as a sister of the Asgard archaea. This implies that there are only two domains of life, Bacteria and Archaea, with eukaryotes incorporated among archaea. Eukaryotes represent a small minority of the number of organisms, but, due to their generally much larger size, their collective global biomass is estimated to be about equal to that of prokaryotes. Eukaryotes emerged approximately 2.3–1.8 billion years ago, during the Proterozoic eon, likely as flagellated phagotrophs. Their name comes from the Greek εὖ (''eu'', "well" or "good") and κάρυον (''karyon'', "nut" or "kernel"). E ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
SAR Supergroup
The SAR supergroup, also just SAR or Harosa, is a clade that includes stramenopiles (heterokonts), alveolates, and Rhizaria. The name is an acronym derived from the first letters of each of these clades; it has been alternatively spelled "RAS". The term "Harosa" (at the subkingdom level) has also been used. The SAR supergroup is a node-based taxon. Note that as a formal taxon, "Sar" has only its first letter capitalized, while the earlier abbreviation, SAR, retains all uppercase letters. Both names refer to the same group of organisms, unless further taxonomic revisions deem otherwise. Members of the SAR supergroup were once included under the separate supergroups Chromalveolata ( Chromista and Alveolata) and Rhizaria, until phylogenetic studies confirmed that stramenopiles and alveolates diverged with Rhizaria. This apparently excluded haptophytes and cryptomonads, leading Okamoto ''et al.'' (2009) to propose the clade Hacrobia to accommodate them. Phylogeny Based on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heterokonta
Heterokonts are a group of protists (formally referred to as Heterokonta, Heterokontae or Heterokontophyta). The group is a major line of eukaryotes. Most are algae, ranging from the giant multicellular kelp to the unicellular diatoms, which are a primary component of plankton. Other notable members of the Stramenopiles include the (generally) parasitic oomycetes, including ''Phytophthora'', which caused the Great Famine of Ireland, and ''Pythium'', which causes seed rot and damping off. The name "heterokont" refers to the type of motile life cycle stage, in which the flagellated cells possess two differently arranged flagella (see zoospore). History In 1899, Alexander Luther created the term "Heterokontae" for some algae with unequal flagella, today called Xanthophyceae. Later, some authors (e.g., Copeland, 1956) included other groups in Heterokonta, expanding the name's sense. The term continues to be applied in different ways, leading to Heterokontophyta being applied ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diatom
A diatom (New Latin, Neo-Latin ''diatoma''), "a cutting through, a severance", from el, διάτομος, diátomos, "cut in half, divided equally" from el, διατέμνω, diatémno, "to cut in twain". is any member of a large group comprising several Genus, genera of algae, specifically microalgae, found in the oceans, waterways and soils of the world. Living diatoms make up a significant portion of the Earth's Biomass (ecology), biomass: they generate about 20 to 50 percent of the oxygen produced on the planet each year, take in over 6.7 billion metric tons of silicon each year from the waters in which they live, and constitute nearly half of the organic material found in the oceans. The Protist shell, shells of dead diatoms can reach as much as a half-mile (800 m) deep on the ocean floor, and the entire Amazon basin is fertilized annually by 27 million tons of diatom shell dust transported by transatlantic winds from the African Sahara, much of it from the Bodélé Dep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fragilariophyceae
Fragilariophyceae is a group of pennate diatoms lacking a raphe. Examples It includes the following genera: Fragilariales *'' Ardissonea'' *''Asterionella'' *''Asterionellopsis'' *'' Catacombas'' *'' Diatoma'' *''Fragilaria'' *'' Fragilariforma'' *'' Grammonema'' *'' Hyalosynedra'' *'' Neofragilaria'' *'' Opephora'' *'' Pseudostaurosira'' *'' Punctastriata'' *'' Staurosira'' *'' Staurosirella'' *'' Synedra'' *'' Synedropsis'' *'' Tabularia'' *'' Ulnaria'' Striatellales *'' Hyalosira'' *'' Striatella'' *'' Toxarium'' Other *''Climacosphenia'' *'' Cyclophora'' *'' Delphineis'' *'' Protoraphis'' *'' Rhabdonema'' *'' Rhaphoneis'' *'' Tabellaria'' *''Thalassionema ''Thalassionema'' is a genus of Chromista belonging to the family Thalassionemataceae. The genus was described in 1902 by Albert Grunow, Grunow ex Mereschkowsky. Species: * ''Thalassionema nitzschioides'' Grunow, 1862 References Fragi ...'' References Heterokont classes {{Diatom-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Climacosphenia
''Climacosphenia'' is a genus of marine pennate diatoms in the order Fragilariophyceae Fragilariophyceae is a group of pennate diatom The order Pennales is a traditional subdivision of the heterokont algae known as diatoms. The order is named for the shape of the cell walls (or valves or frustules) of pennate diatoms, which a .... References External links * * * * Diatom genera Fragilariophyceae Taxa named by Christian Gottfried Ehrenberg {{Diatom-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mereschkowsky
Konstantin Sergeevich Mereschkowski ( rus, Константи́н Серге́евич Мережко́вский, p=mʲɪrʲɪˈʂkofskʲɪj; – 9 January 1921) was a prominent Russian biologist and botanist, active mainly around Kazan, Tatarstan, whose research on lichens led him to propose the theory of symbiogenesis – that larger, more complex cells (of eukaryotes) evolved from the symbiotic relationship between less complex ones. He presented this theory in 1910, in his work, ''The Theory of Two Plasms as the Basis of Symbiogenesis, a New Study of the Origins of Organisms'', although the fundamentals of the idea had already appeared in his earlier 1905 work, ''The nature and origins of chromatophores in the plant kingdom''. Biography Early life Konstantin was born in Saint Petersburg, one of six sons and three daughters in the Mereschkowski family. His father Sergey Ivanovich served as a senior official in several Russian local governors' cabinets (including that ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Species Described In 1901
In biology, a species is the basic unit of classification and a taxonomic rank of an organism, as well as a unit of biodiversity. A species is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. Other ways of defining species include their karyotype, DNA sequence, morphology, behaviour or ecological niche. In addition, paleontologists use the concept of the chronospecies since fossil reproduction cannot be examined. The most recent rigorous estimate for the total number of species of eukaryotes is between 8 and 8.7 million. However, only about 14% of these had been described by 2011. All species (except viruses) are given a two-part name, a "binomial". The first part of a binomial is the genus to which the species belongs. The second part is called the specific name or the specific epithet (in botanical nomenclature, also sometimes in zoologica ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pennales
The order Pennales is a traditional subdivision of the heterokont algae known as diatoms. The order is named for the shape of the cell wall#Diatom cell walls, cell walls (or valves or frustules) of pennate diatoms, which are elongated in valve view. The valves may be linear or oval in shape, and usually bear Symmetry (biology), bilaterally symmetrical ornamental patterns. These patterns are composed of a series of transverse lines (known as striae) that can appear as rows of dots when viewed with an optical microscope. Some pennate diatoms also exhibit a fissure along their longitudinal axis. This is known as a raphe, and is involved in gliding movements made by diatom cells; motile diatoms always possess a raphe. In terms of cell cycle, vegetative reproduction, vegetative cells are diploid and undergo mitosis during normal cell division. Periodically, meiosis produces morphology (biology), morphologically identical haploid gametes (isogametes), which fuse to produce a (somet ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
.jpg "Click for more on -> Mereschkowsky")
